List finder



Sept. 5, 1950 A. E. POLLOCK 2,521,407

' 'LIST FINDER Filed June 17, 1947 5 Sheets-Sheet 1 lll!lllllll lll l .'k\bhllllylllllllllll-lqi'|| &

Q T JNVENTbR.

Sept. 5, 1950 A. E. POLLOCK 2,521,407

LIST FINDER Filed June 17,1947 5 Sheets-Sheet 2 Q I I I I I INVEN TOR flLberiEpollodi P 1950 A. E. POLLOCYK 2,521,407

LIST FINDER 5 Sheets-Sheet 3 Filed June 17, 1947 INVENTOR fllberZEPoLZocli ept 5, 1950 A. E. POLLOCK 2,521,407

LIST FINDER Filed June 1'7, 1947 5 Sheets-Sheet 4 ]N VEN TOR.

flibcriE. Polloc/Z Sept. 5, 1950 I A. POLLOCKQ 2,521,407

usa- FINDER Filed June l7. 1947 Sheets-Sheet 5 INVENTOR ATTORNEYS Patented Sept. 5, 1950 UNITED STATES PATENT OFFICE LIs'i'rINDEit Albert Edward Pollock, New York, N. Y. aiifilieetioirjinie 17, 1947; Serial No; 755360 15 claims; (0140-404) 1 The present invention relates to list finders and articularly to that type of list finder in which a plurality" of sheets are indexed and mea s are provided to automatically select any one of the index sheets.

More particularly still the invention relates to a list finder of the eneral type disclosedi-n iny Patent No. 2,141,761 of Decenibertfl, 1938, and is an improvement upon that list finder. The improvement resides p'riinarily in the fact that the index is given an enhanced appearance and that the assenibly of the various pai ts is much more simply and economically performed;

It is adobj'eot of the invention to provide a list finder or automatically selectable index in which the arts are so arranged as to'inake the assem= bly extremely simple.

It is another object of the invention to provide an improved means for causing the cover orsuoh index to be sprin'ghiased to its open position;

It is afurtlier object of the invention to provide a list finder of the type described in which the parts are simple andare extremely economically produced;

Gthi objects and features of the invention will be a parent when the following description is con-- siaered in connection with the annexed drawings in which:

Figure I is a top plan view of the index orrnv invention;

Figure 2 is e front elevation of the index with the cover in its open position;

Figure 3 is a 1engitddii1a-Lvertiee1, cross-section taken on the plane or the l-ifi'3--"-'3 or Figure 1; Figure 41s a Bottom lan view ofthe-holder' for theindex Sheets and the sad (if index Sheets therein;

Figure 5 is e s'id'el'evation of the holder and pad; of Figure 4; p I Figure 6' is a transverse vertical cross se'c'tion oithe list finder of Figure 1- tak'enon the inane of the line 6-4; of Figure 3;

Figure '7 is a bottom p1an vivlfofthe list finder of Figure I';

Figure 8' is a detail cross-sectional view or the controlling button or knob showing the inode ihwhich it is spring detented and held in selected esiti'on;

Figure 9 is a fragmentary cross-sectional view of the list finder taken on the plane ofthel'ine 9 90f Figure 7. In this view the cover is in itsopen position so that the view shows the methodof forming detentin'g surfaces on the-under side of the cover; 7

Figure lit)" is a; fragmentary top plan view ofthe cover for the list finder 1 Figure 11 is a bottom plan view of the cover 0 Figure 10;

Figui c 12 is a perspective viewof the holder for the index pad;

Figure 13 is a perspective view of the saddle member which holds the cover in position for pivotal movement with respect to the base;

Figure 14 is e perspective view of a device for holding a pacl: of index sheets within the base, this device being an alternative to that of Figure 12; 1

Figure 15 is a fragmentary bottom view of the base'of the index showing the device of Figure 14 in place;

Figure 16 is a frag'inentary longitudinal crosssection of the index showing one rnode'of assuring the correct placement of the index sheets when the holding device of Figure 14' is utilized;

Figure l'lisa fragmentary cross-sectional view of a portion of the index showing the mode of utilizing the latch member to assure correct position of the sheets in the index;

Figure 18 is a fragmentary view of the index taken on the plane of the line 19 a of Figure 18;

Figure; 20 is a view similar to Figure 18 illustrating a further modification or the eon-former tion of the index base in order to assure correct positioning of the index sheets, and

Figure 21 is a top plan view of a single sheet of the pack or sheets utilized in the index.-

Reie'rring' to the drawings, the list finder of present invention comprises a base I. This base I is provided with a rini 2 and a central depression 3 (see Figure 6). stantially rectangular in form.

Hinged to the base I in a r'n'anner hereinafter described is a covert, which cover i normally held in'its closed position by means of alatch 5 which cooperates with a projection 6 at the forward end of the'cover 4.

The bad of index sheets generally designated 7 (Figure 4 is held iri a- Holder 8, which holder is provided with depending ears 9 which fasten the .1. Formed integrally with the base I' and the rear- The central well 3 is sub" ward portions of the rim 2, as well as the ledge II, are depending ribs I2 which are located centrally of the rear of the base and spaced apart, these ribs forming guide members for a hinging portion of the cover which will shortly be described. The forward edge of the ledge II is depressed below the remainder of the ledge and given a concave formation I3, this concave forwardly extending portion being broken away at the center between the ribs I2 and thus extending outwardly from each rib E2 to the rim 2.

The cover 4 is formed at its rear edge with a rounded portion I4 which mates with the concave edges 13 and forms a pivotal knife edge type connection or hinge between the base and cover. The cover 4 is provided with the U-shaped member I5, illustrated particularly in Figures 10 and 11, which member extends rearwardly from the cover and the main portion of which lies slightly below the plane of the cover 4. Member I5 extends rearwardly between the two ribs l2 being held in position by means of a saddle [3 (Figure 13) one end of which seats in a groove l! in a thickened portion I8 of a depending rib I 9 formed integrally with the base I. The other end of the saddle member I6 is bent over, as shown at 23, and seats against the undersurface of the ledge II. The saddle member I3 has the form of a quarter circle and thus after being inserted into the, base as described above and through the U-shaped member I5 of the cover l holds the cover in position with the rounded edge I4 in contact with th concave portion I3 of the ledge II. Thus these elements form a pivotal connection between the base I and cover 4 of the device.

A coil spring 2| is fastened at one end in the groove 22 of the crossbar f the U-shaped member I and extends in contact with the curved portion of the saddle member I6 and forwardly being fastened at its other end to the base I at approximately the center thereof, this fastening being by means of a hook member on the end of the spring which engages a hole 23 in the base I. The spring 2! is held in position transversely of the underside of the base I by means of depending ribs 24 formed integrally with the base. The depending ribs 24 are reinforced by means of a transversely extending rib 24a formed integrally with the base It will be seen from the above description that the spring 2| in addition to urging the cover towards its open position likewise serves to hold the saddle member It in its position as already described.

Cover member 4 is provided with a slot 25 extending longitudinally thereof along its center line. On either side of this slot on the upper surface of the cover is a ridge 26 on which an operating button is positioned for sliding movement as will be hereinafter described. On either side of the undersurface of the cover a ridge is also formed, these ridges, however, being provided with tooth-like members 21 with which the operating button cooperates in a manner shortly to be described in order that the button may be detented and held in a selected position.

The operating button which is positioned for sliding movement along the slot 25 is shown in detail in Figure 8. This button comprises the button member proper 28 which is provided with a cavity 29 in its under-surface as well as with the downwardl extending projections 30 which extend through the slot 25. In the cavity 29 there is placed a small coil spring 3I, this springbeing compressed between the upper. face of the 4 cavity 29 and a washer 32 which makes contact with and is supported by the ridges 28. A member 33 extends across the bottom of the slot 25 and makes contact with the teeth 2'! formed on the ridge portions of the underside of the slot. Member 33, as will hereinafter appear, cooperates with the pile or stack of index cards held in the well of the base I and selects the particular card which is exposed'to view in accordance with the position of the button 28. The spring 3| constantly urges the operating button upwardly and "thus urges the member 33 upwardly into contact and the holder being provided with a cutout 35 at their rear edges in order to avoid interference with the U-shaped member l5 and with the depending ribs I2 already described. Each card of the stack is provided with a notch 35a in each of its side walls towards the rear, these notches cooperating with the bent over portions 36 of the side walls of the holder 8. These sheets or cards may be very readily inserted in the holder by merely bending the sheets into a convex form and then inserting them in the holder with the notches positioned under the bent over lugs 36. The cards areheld in position on the holder 8 by means of the bent over lugs 36, already described, as well as by the bent up edges 31 (see Figure 12).

After the cardshave been inserted in the holder 8, this holder is in turn positioned within the well or cavity of the base I with the rearward ends of the holder and of the cards lying under the ledge II and between the outside walls of the rim portion 2 of the base and the ribs I2. The card holder is held in position by means of the downwardly extending ears 9 which pass through slots 38 in the bottom of the base I and grip the sides of these slots. Finger holes 39 are provided in the base, as shownparticularly in Figure '7, in order to render it easy to remove the card holder when desired, it being only necessary to press against the bottom of the card holder 8 and thus release the ears 9 from the slots 38 and permit removal of'the card holder and the card stack thereon.

The latch 5 previously mentioned is formed from spring material being bent into the shape of an L and having the button proper 5 integral therewith and mounted at the upper end of the L. The other end of the spring member which is designated 40 extends beneath the central portion of the base between two depending ribs 4| and is fastened to the base in any suitable manner, as, for example, by means of the rivet 42. The latch member 5 is provided with a curved portion 43 which cooperates with the projections 6 on the cover 4 already mentioned and thus normally holds the cover in its closed position.

The selection of the cards is effected, as has been described, by moving the selecting or operating button 28 along the slot 25 to a preselected position. Since the member 33 is provided with depending arms 44 which extend downwardly and then inwardly beneath the index tab portions 34 of the card stack 1, the position of the buttonv ifiwlndetefimmatne. an oi: cards which fare. to be carried upwardly: witl ithei-eovel aseit moves snbseqileneto releaseby the'lsitoli memloerr'i :As is -iilfiie'a-ted PQI' -flicii-IFI IY -S't 4'5 (l'ifi-lFigm e: 59: the cams are: scored along lines; successively greaten distances 15mm the: rear; considered fromzthe top downwardly; Thus a: proper piwot-pointgis providedlforthe rotation at each: card: about itsown score 1ineand,..as:deseribed,the. selected card may be exposed: to v iewlbyl causing all the] cards. above it to he rotated'about their respectivescore linescand carried upwardly, withthe e'overl v FiguresM and 15'il1ustrate another methodlofi holdingthepaok of index sheets 1- il pl operv position the cavity- 3 of the base; ll this fastening means is utilized the metals device. 8-'of Figure l2 is dispensedwithand theshe'ets-are not notched to accommodate the lugs 35 but are straigh-t along-their rearward side; edgesl x The device of. Figure l4; com-prises a strip of somewhat resilient metal 46 which is} bent into theshape illustrated in Figtli-'e 14 beina provided with the angled flanges 41 whiehaswi'll apeal are adapted to grip the-sides of the base fto hold this resilient member. 16 andthe sheets thereon proper position, Also the metallietainer Eli'is provi'ciedvwith the-raised areas fi -infiol der to more firmly grip the sheets. toliiol'cl them in. position. Thedevicelfit fl's insert'diih tlilreai of't'l ie base from the iiiidefside thereof 'iii Sl'lh manner that the sides EQ'of the depi'ssedfitfalafa'lifi'lie' on. the outer edges 61? thetwo fills [2' and raised areas piessagainstthelowennost sheet of a stack of sheets which is inserted into the ease with the ia"""afii edges Whig" iritl'l 5W6 outer rectangular oes. The pack of sheets is time held between the: raised areas 4'8 of the member 46' and. the. depres ed portion; is of; the forwardly extending ledge H. hy e means deselibedtlie pack of sheets is vefy'feadily heist-lo its proper position'iii' the Base!" and tlrenecessity for the nilnb'ei' Saswei-Las fi helioies 39 and slots 38* is dis ensed Wltli. Additionally, can readily he sen the manufacture-of the piece is involves colislderalll'y lessexpense than is true of the member aso that the use fimelnter awe the east of the (levies Both respeets the base'an-d'as res ects the-member. itself; fine to the factthatwhen meinher 461's ntillzed the sheets are held only by the erlpplnfgelfe'ot producedhy thepositionl'ngof'inernbrfl within the cavities at the'iearward portion'ofthe Base and resting against the ribs I2,. there is a possibility' that" the-sheets will move foiwardly and thus'get out ofall'gfl' entz Giiemdde of pi-e= venting this result" illustrated in 16'. As shown'in; this heme, the eover member I is plot-rides with" pins or resilient members it one oneither side thereof nean the leeward ease: these 'plnsmoving withthe cover throughan are; as indioateci by the clash line, afiolit the center of the extension" H: of theeovee l. lie against theedgesof the-tab eutotltsin-tho sheet l,- the sheet-s Being out so that although thescore across "lie pro gressiveh 'furthehto the rearfrom the bc'att clln-of upwardly, the edges of these cute cover-- 8* is 'olosedthe pins hennagainst the edges of the cutoutssense the sheets to move reaewarcl' ly against iafbeffioh of" the 2; Therefore, wlimew-er the' moves the sheets-ale firth-ope? reels-tense that the de sired tab 34 is selected. I 3 A lin't hemoode or ch' vanilla-same feslillt eels illustrated Fle t'sare even. sis-the are 1"}.- r Inthi'sinstance a pin 52- is fastened to the latchmember 40 near the forward edge thereof, this pinbeing adapted to move againstthe forward edges of the sheets 1- and-thus. cause them who moved rearwardly against the rear-- ware edge of the rim z'tlpon' each return of'the latch 40 and the operating member 5 to latching positiol'i; 1

Instead of permitting'someplay of. the: sheets withinuthe: cavity 3 of the base and correcting any displacement by means of the pin 5| on pin 52, it is possible to slightly alter the formof the base andv thus prevent any movement of the sheets. Figures 18 and 19 illustrate one modein which the base cavity" 3 may be formed to prevent suchmovement of the sheets. In this'in stance; the ledge 53 with which the base I is provided and on which the depending edge of the cover ll seats is provided with a pair of generally cylindrical projections ti -i one near either-side which bear against the forward edges of the sheets 1. lnorder. to prevent the sheets 1 from moving forwardly above the projection 53', a-pai'r of pins 5t formedl integrally. with the cover lane provided,.- these pinsforeingthe sheets down in such a manner as to cause them to rest against the projections t5 and prevent any movement whatsoeven The same result as was achievedby use of'the projections 54 is secured. in anotherlnanlier as shown in Figure 20. Here. the cover is again provided with the "21s 5-5 but instead of provid ing the oylinerlcalprojeotions '58 on the ledge-53 the forward eoges or the sheetsare made to conform to" the shape oftli'e ledge 53'. Clearly this p vents any movement oflt'he sheets since the 55" Cause the sheetsito' he held beneath the uppe edge" of the ledge 53' during movement of the slider 28 and thus the sheets cannotbe moved except in the" unusual event of accidental droppin fof the device While the cover 4 is open.

- in order'to revent the device from scratching or markingthe surfaeonwhich it'rnay rest, the base I is provided with small cavities into which H piece-sol suitable material such as rather orfeit may be inserted to act as root 5-staprevent snoh marking. I

While I have described a prefenedformof my invention, it will be understood that various modifications are possible and I do not desire; therefore; tote-limited by the1''oregoing desori'p-- tion but solely by the scope of theclaims granted What is" claimed is:

1. in the list finder of the class described, in combination, a base of generally rectangular form, having a rim integral therewith and forniin a well for a pack of indexed sheets, a cover fitting over said sheets, said cover'havih'ga downward-1y extending rounded surface at the rear edge thereof, a con-vex surface onthe rear of the rim of sale base, said convex surface cooperating with said rounded surface of said cover to form a hinge for said cover, and means for holdl'ng saideover' surface against said Base rimsunface. r

2. In the list finder oftheclass' des'oriheli, in combination, a base of generally rectangular form, having, a rim'i'ntegl'al therewith, forming-a well for a pack of indexed sheets;- a' c'overfitti'ng over said sheets; said-cover havlng'adhwnwardiy extending-rounded surface at the T631" edge" thereof; a convex surfacefomed on the-upper ease-of ther'ear therlm of saidbase woo en-w: ing with said" Founded surface of solo "owerto form a hinge for said cover, a U-shaped member extending rearwardly from said cover at the center thereof, and a saddle member mounted in the base and extending through the said U- shaped member to hold the said rounded surface of the cover against said convex surface of the said ledge.

3. In the list finder of the class described, in combination, a base of generally rectangular form, having a rim integral therewith forming a well for a pack of index sheets, a cover fitting over said sheets, said cover having a downwardly extending rounded surface at the rear edge thereof, a ledge formed on the rear of the rim of said base, said ledge extending forwardly and terminating in a convex surface cooperating with said rounded surface of said cover to form a hinge for said cover, a U-shaped member extending rearwardly from said cover at the center-thereof, a saddle member mounted in the base and extending through the said U-shaped member to hold the said rounded surface of the cover against the said convex surface of the said ledge, and a coil spring fixed to the crossbar of said U-shaped member, said spring extending forwardly and in contact with said saddle member and having its other end fixed to said base, whereby said spring biases said cover to open position.

4. In a list finder of the class described, in combination, a base having an integral, upstanding rim, said base being generally rectangular, a cover hinged to said base, said hinge comprising a convex surface on the rear of said cover and a concave surface formed in a forwardly extending ledge integral with said rim, said ledge lying substantially in the plane of said cover, a pair of ribs formed integral with the said ledge and the said rim, said ribs being spaced apart and lying-one on either side of the center line of said device, a U-shaped member formed integral with said cover, and extending rearwardly between said ribs and means cooperating with said U-shaped member for holding said convex portion of said cover in contact with said concave portion of said ledge.

5. In a list finder of the class described, in combination, a base having an integral upstanding rim, said base being generally rectangular, a cover hinged to said base, said hinge comprising a convex surface formed on the rear of said cover and a concave surface formed in a forwardly extending ledge integral with said rim, said ledge lying substantially in the plane of said cover, a pair of ribs formed integral with the said ledge and in the said rim, said ribs being spaced apart and lying one on either side of the center line of said device, a U-shaped member formed integral with said cover and extending rearwardly between said ribs, means cooperating with said U-shaped member for holding said convex portion of said cover in contact with said concave portion of said ledge to form the hinge between said base and said cover, a rib extending across the base adjacent the forward edge of said first mentioned ribs, an open slot in said last mentioned rib, and a saddle member having the configuration of a 90 circle arc, said saddle said first mentioned ribs, and serving to hold said convex surface of said cover against the'said concave surface of said ledge.

6. In a list finder of the class described in combination, a base having an integral upstanding .rim, said base being generally rectangular, a cover'hinged to said base, said hinge comprising a convex surface across the rear edge of said cover and a concave surface formed in a forwardly extending ledge integral with said ribs, said ledge lying substantially in the Plane of said cover, a pair of ribs formed integral with the said ledge and the said rim, said ribs being spaced apart and lying'one on either side of the center line of said device, a U-shaped member formed integral with said cover and extending rearwardlybetween said ribs, means cooperating with said U-shaped'member for holding said convex portion of said cover in contact with said concave portion of said ledge to form the hinge between said base and said cover, a rib extending across the base adjacent the forward edge of'said first mentioned ribs, an open slot in said last mentioned rib, a saddle member having the configuration of a circle are, said saddle member having one end mounted in said slot and the opposite end bent over and bearing against the under surface of said ledge at the rear thereof, said saddle member extendin through said U-shaped member, and between said first mentioned ribs, and serving to hold said convex surface of said cover against the said concave surface of said ledge, a coil spring having one end fixed to the cross bar of said U-shaped member, means anchoring the other end of said coil spring to said base adjacent the center thereof, said spring extending over said saddle member and holding said saddle member in position, and webs extending downwardly from the central portion of said base, one on either side of said coil spring to protect said spring and hold it in its proper position.

7. In a list finder of the class described, in combination, a base having an upstanding rim thereabout, and forming a central well having a groove on either side thereof, a cover hingedly mounted on said base, and a pack of tabbed index cards mounted in said well, with their edges extending over said grooves, and a holder in which said index cards are mounted said holder having downwardly extending ears which extend through holes in saidbase and position said index card holder.

8. In a list finder of the class described, in combination, a base, an upstanding rim integral with said base forming a cavity of generally rectangular shape having longitudinal grooves of greater depth than the cavity along the edges thereof, a ledge extending forwardly from the rear wall of said rim, a pair of ribs extending forwardly from the rear wall of said rim and made integral with said rim and said ledge, said ribs being spaced on either side of the center line of the list finder, and a holder for tabbed index sheets, said holder comprising a sheet metal stamping having upwardly extending ears adaptedto hold a pack of index cards thereon, and having downwardly extending ears adapted to hold said holder in position on said index base, said stamping having rearwardly extending projections formed to fit within the spaces between the said ribs and the rearward side portions of said upstanding rim.

' 9. In a list finding device of the class described in combination,-a base having an upstanding rim forming a central cavity, said cavity having its longitudinal edge portions of greater depth than the remainder forming grooves, a cover hingedly connected to said base by means of a knife edge hinge, a coil spring for biasing said cover to its open position, a slot extending longitudinally of said cover, a card selecting member mounted in said slot, said member having downwardly extending portions terminating in inwardly bent ends, a pack of tabbed index cards mounted in said cavity with their edges extending over the longitudinal portion of the cavity of greater depth and lying above the said bent terminating ends of said card selecting member, and spring pressed means for holding said card selecting member in a selected position along said slot, whereby upon release of the cover to open position, the selected index sheet will be exposed to view.

10. In a list finder of the class described and having a base with a cavity therein and a cover hingedly secured thereto, in combination, a pack of cards mounted on said base each card being scored to permit oscillatory movement of the free end thereof, means mounted on said cover for selecting the number of said index cards to be pivotally moved with said cover, said means comprising a longitudinal slot in said cover, the edges of said slot being raised above the plane of the cover, a button having depending portions extending through said slot, a cavity in said button, a coil spring mounted in said cavity, a washer extending across said slot between said downwardly depending members, and serving to compress said coil spring between said button and said washer and a card selecting member fixed to said downwardly extending members, said card selecting member extending transversely of said cover and having downwardly extending portions adjacent its ends, said downwardly extending portions terminating in inwardly extending portions which cooperate with the tabbed index cards.

11. In a list finder of the class described, and having a base with a cavity therein, and a cover hingedly secured thereto, a pack of cards mounted on said base, each card being scored to permit movement of the free end thereof, in combination, means mounted on said cover for selecting the number of said index cards to be pivotally moved with said cover, said means comprising a longitudinal slot in said cover, the edges of said slot being raised above the plane of the cover, a button having depending portions extending through said slot, a cavity in said button, a coil spring mounted in said cavity, a washer extending across said slot between said downwardly depending members, and serving to compress said coil spring between said button and said washer, a card selecting member fixed to said downwardly extending members, said card selecting member extending transversely of said cover and having downwardly extending portions adjacent its ends, said downwardly extending portions terminating in inwardly extending portions which cooperate with the tabbed index cards, toothed ridges on the underside of said slot ad 10 jacent the edges thereof, and a rounded central portion of said card selecting member, said portion cooperating with said teeth and forming with said spring pressed button, a means for detenting said card selecting member at a desired position.

12. In a list finder of the class described having a base with a cavity therein, a cover removably hingedly secured thereto and a pack of cards mounted within said cavity, in combination, means for holding the pack of cards in the cavity of the base, said means comprising a rim on said base, a ledge extending forwardly from the rear of said rim, extensions of said cards extending rearwardly beneath said ledge, and a resilient metallic piece fitted within the rearward portion of said base from beneath, said member cooperating with said ledge to hold the sheets therebetween.

13. In a list finder of the class described having a base with a cavity therein, a cover hingedly secured thereto and a pack of cards mounted on said base within said cavity, in combination, a pair of pins fixed to the underside of the cover adjacent the side edges thereof, and notches in said cards forming index tabs, said pins striking against the enlarged rear edges of said sheets to thereby move said cards into position upon each closure of the cover.

14. In a list finder of the class described having a base with a cavity therein, a cover hingedly secured thereto and a pack of cards mounted within the cavity of said base, in combination, latch means for holding said cover in its closed position, and means mounted on said latch members for making contact with the forward edges of said cards as the latch is moved to latching position, said means thereby serving to position said cards in registration upon each latch operation of said latch member.

15. In a list finder of the class described having a base with a cavity therein, a cover hingedly secured to said base and a pack of cards mounted within said cavity, in combination, a projection extending into said cavity from the forward edge of said base, said projection defining the cavity and causing registration of the sheets, and means projecting downwardly from the forward edge of the cover to cause said sheets to bear against said projecting means.

ALBERT EDWARD POLLOCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 811,489 Dunwell Jan. 30, 1906 1,094,716 Hill Apr. 28, 1914 1,637,485 Hiering Aug. 2, 1927 2,115,537 Peter Apr. 26, 1938 2,141,761 Pollock Dec. 27, 1938 FOREIGN PATENTS Number Country Date 681,977 Germany Oct. 5, 1939 

